Fluid pressure operated vise



March 18, 1947.

G. F. BATES 2,417,625

FLUID PRESSURE OPERATED VISE Filed Sept'. 6, 1944 2 Sheets-Sheet l lNl/ENTOR .Geolg Z A 7' TORNEY Patented Mar. 18, 1947 FLUID PRESSURE OPERATED VISE George Francis Bates, Worcester, England, as-

signor of one-half to The Mining Engineering Company Limited, Worcester, England Application September 6, 1944, Serial No. 552,926 In Great Britain October .6, 1943 3 Claims. 1

This invention is designed to provide a simple form of fluid pressure (preferably compressed air) operated vise more especially for machine tools. A vise may have to maintain its grip Tfor fairly considerable periods of time. Leakage of the pressure fluid should be reduced to the slightest and the use of glands or packings requiring maintenance avoided.

In a vise according to the present invention a double ended piston is used ina cylinder which is permanently closed at that end to which pressure toclose the vise .is applied, power being transmitted from an intermediate portion of the piston and the pressure fluid being admitted to, or exhausted from, either end of the cylinder by simple cock control. In the preferred form a vertical cylinder and a fixed jaw of the vise are at one end of a bed with a slideway on which the movable jaw is slidable, the movement being applied by a bell crank lever pivoted under the slideway. The lever can engage a member relatively to which the movable jaw is adjustable, so that a small movement will serve to grip or release work f any size within the maximum jaw opening.

Other parts of the invention are embodied in a typical form illustrated by the accompanying drawings, the parts for which a monopoly is desired being those delimited by the claims.

In the drawings:

Fig. 1 is a longitudinal sectional elevation on the line |-l of Fig. 3.

Fig. 2 is an end elevation, and

Fig. 3 is a plan view.

A main casting comprises a hollow bed portion I on the upper part of which is a T-slideway 2. External flanges 3 are provided for clamping it (as by clamp 4) in desired position on the usual machine tool table, tenons 5 being attached. At one end there is formed a vertical cylinder 6, the upper end Ba of which is closed and the lower end of which is covered by an end plate 1 secured by screws. The fixed jaw 8 of the vise is secured to the side of the cylinder and the moving jaw 9 is secured to a block l0 slidably mounted on the main casting, attached strips l I engaging the slideway 2.. A bell crank lever is pivoted on a swivel pin l3 in the main casting and one arm I2 extends approximately horizontally into the cylinder while the other H! is forked as conventionally illustrated by the dotted line in Figure l and extends approximately vertically, the forked ends passing on either side of an adjusting screw IS in the sliding block 10 and engaging in exactly similar recesses on the two sides of the nut Hi through which the screw operates. The ad. lusting screw is held in the sliding blockby 'a thrust collar l5a integral with the screw and by a securing member I! bolted to the block.

A double ended piston l8 each end of which is fitted with piston rings [9 operates in the cylinder. The centre of the piston is slotted to receive the rounded end 12a of the horizontal arm 12 of the bell-crank lever, the point of 'contact being approximately on the centre line "of the piston.

A simple two way cock bolted to the main casting admits compressed air to oneor other end of the cylinder from the supply line 20 through drilled passages 2! or 22 and simultaneously opens the opposite end to atmosphere through a silencer 23 which also excludes swarf and dirt from the mechanism. The tapered plug 24 of the cock is kept tight by a spring 25 and its limiting positions are controlled in a conventional manner by a stop peg 2B engaging in an arcuate groove 26a in hand-wheel 21.

It will be appreciated that the slidin block can be set in any desired position to suit work of different sizes by means of the adjusting screw so that the work to be held can be easily put in or taken out and operation of the air cock to admit high pressure air to the upper end of the cylinder and. to open the lower end of the cylinder to atmosphere causes the piston to move downwards and thus closes the jaws on the work by means of the bell crank lever. Similarly operation of the air cock to admit high pressure air to the lower end of the cylinder and exhaust the upper end opens the jaws and releases the work.

The flow of air to one or other end of the cylinder may be suitably restricted to modify the speed of movement of the jaws and a reducing valve provided to control the pressure exerted by the jaws 0n the object held.

It will be understood that, when the vise is holding the work, only the permanently closed end of the cylinder is subjected to air pressure and load of the piston, transmitted through the bell crank lever, nut and adjusting screw collar, is operating on the sliding block Ill. The secure holding of the work is thus not dependent on packings, glands, bolts or the like.

I claim: I

1. A fluid pressure operated vise having a movable jaw, a cylinder with one end permanently closed, a glandless cylinder head completely closing the other end of said cylinder, a double ended piston in said cylinder, valve means arranged to supply pressure fluid to either end of said cylinder at will and to simultaneously open the other end to exhaust, and power transmission mechanism passing through the cylindrical wall of said cylinder and engaged by an intermediate portion of said piston, and arranged to close said jaw when pressure fluid is admitted to the permanently closed end of said cylinder and to open the jaw when pressure fluid is admitted to the other end of said cylinder, the power transmission mechanism including a sliding member and means to adjust said movable jaw relatively to said member.

2. A fluid pressure operated vise having a movable jaw, a glandless cylinder with both ends closed, a double ended piston in the said cylinder, valve means arranged to supply pressure fluid to either end of the said cylinder at will and to open the other end to exhaust, and power transmission mechanism engaged by an intermediate portion of said piston and arranged to close said jaw when pressure fluid is admitted to one of saidclosed ends of said cylinder and to open the jaw when pressure fluid is admitted to the other closed end of said cylinder, the movable jaw of the vise being slidable upon a hollow bed and the power transmission mechanism including a bell crank lever pivoted on a substantially horizontal axis within said bed and passing through the cylindrical wall of said cylinder into engagement with an intermediate portion of said piston,

the power transmission mechanism including a sliding member and means to adjust said movable jaw relatively to said member.

3. A fluid pressure operated vise having a substantially vertical cylinder with its upper end permanently closed, a glandless cylinder head closing the other end of said cylinder and a fixed jaw at one end of a bed with a slideway on which a movable jaw is slidable, a double-ended piston in the cylinder and a bell crank lever under the slideway having a longer more or less horizontal arm passing through the vertical wall of said cylinder and engaging an intermediate part of the piston near its center line and a shorter more or less vertical arm engaging a member relatively to which the movable jaw is adjustable.

GEORGE FRANCIS BATES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 486,723 -Loss Nov. 22, 1892 884,548 Warwick 1 Apr. 14, 1908 1,060,477 Meyers Apr. 29, 1913 1,375,928 Olson Apr. 26, 1921 1,619,340 Fullerton Mar. 1, 1927 1,638,258 Halleck Aug. 9, 1927 311,335 Garrigus et a1 Feb. 16, 1943 568,364 McIntyre Sept. 29, 1869 2,345,401 Lindegren Mar. 28, 1944 FOREIGN PATENTS Number Country Date 451,049 British July 29, 1926 687,015 German Jan. 20, 1940 

